360 with B&M 10239 scalloped flexplate. externally balanced assy. I wanted as much TC into the trans rearward engagement as possible so I have these (4) button head bolts that weigh 8 grams each & the nuts to take up that distance from the back side of the plate to the (4) TC flat pads & the nuts weigh 3 grams each. the OE bolt weighs 9 grams each. will this cause a balance issue? thank you for your time.

That little bit of weight shouldn't have a noticeable effect.
Specially since they're an equal distance apart I see no problem.

If you are trying to do what I think you are it's a mistake. I think you are going to put the long end of the capscrew through the torque converter lugs and use the nut for a spacer. I do not see this ending well. There isn't much material for the torque converter lugs to press against. The function of that bolt is to apply pressure to the interface so there is enough friction to push the car forward. It's not like those bolts are primarily loaded in shear. They should be primarily loaded in tension.. Now they are going to be in shear and bending. The flexplate is also going to want to bend.

All this for 0.2" more torque converter engagement? Don't do it. A solid crank spacer would be much much better, but I really think you are overthinking this. Remember the cooling issues a while ago?

R.

I don't believe you can get equal tq on all the bolts but if you were to drill out the nuts to a sleeve tight fit would help but I believe the sleeve should be hardened steel.I am going to use an ARP washer from a head bolt kit but it is only .118" .

How thick are the nuts and what makes you need that much space?The impeller drive should be .125+ to .188"out from the pump I was told .

What got me going on this was reports of 904 pump/tc snout related racing failures from iirc not enough engagement. Alright I am gonna take you guys' advice & leave it OE, Dog, the 5th fireup on the head gasket from Hell eng will be in several days!

Are you going to split the difference or run against the flex plate all the way?

there's the balance factor plus the shear issue & I did not even measure the total spacing difference. With my OCD history of fixing problems that don't exist in the first place (such as the cooling situation!) I think I better K.I.S.S. & stay with OE. But I am still open to persuasion (on this one!).

I could only get .200+ until the input of the trans bottomed in the vert.I took that and measured the vert bolt pad from the front of the trans[.630 ish] and also measured the flex plate from the back of the engine .380 ish. on a 727 RB tho.I also greased the vert input and slid it in the trans and looked where the grease ring was when removed to hel get the depth of the drive to pump.I hope this helps.

I think you are now on the right track.

If you really wanted to space the TC away from the flexplate I'd suggest welding little pieces of steel strap to the torque converter lugs. But how would you get it so they're all the same height?

R.

I am going to use ARP washers from a head bolt kit

Why don't you fix the underlying issue rather than bandaid something in and introduce more problems.

Do you actually have a lug engagement issue?

What is your current engagement and why do you think that is a problem?

this is in the 360/904 stock car no problems in that area but people have reported issues there (lug engagement) & if I can head off a potential issue with a simple fix (like doing this) then I am up for it. I was over there today getting the eng ready to fire & FYI the TC has 3/8" fore/aft play and the nut(s) I used in the pic that I was considering were half that (3/16).

Wow,The lug on a stock pump gear is just over .500 tall.

I think most of the reported problems are because of racers using a GM core and hub. Most of the 8" cores are GM. Just because it has a ring gear welded to it doesn't make it a Mopar. The pump engagement is critical on aftermarket, racing converters not OEM. My .02 for what it's worth.

Dave that is good to hear. Thank you. yeah I got enough real problems on this without dreaming up more of em!. it just seemed like 3/8 was alot of freeplay distance.

You can try it with a hard washer/spacer[.100+"] and remove it if it shakes or you just don't want it.Good luck to ya.

thanks brother & in a day or so, the head gasket from Hell issue will (hopefully) be a done deal. I'll know when I fire it up. 5th time's a charm.